1. Field of the invention
The present invention relates to a method and apparatus for bending and cutting metal tubing in a single operation. More particularly, the present invention relates to a method and apparatus for making bent metal tubing pieces in a very precise and reproducible manner, and in which the same machine is operable to perform feeding, bending and cutting operations in an efficient manner. Even more particularly, the present invention relates to a method and apparatus for bending and cutting multiple sections of metal tubing from a single piece of tubing stock.
2. Description of the Background Art
Many types of tubing benders have been developed and are known. Some examples of tubing benders may be found in U.S. Pat. No. 3,724,256, 4,126,030, 4,606,250, 4,703,678 and 5,025,651.
In the previously known methods for manufacturing of short pieces of steel tubing, such as, e.g., exhaust tubing, often times short lengths of straight pre-cut tubing are manually fed, one-by-one, into a machine by an operator. This material may be either stainless steel or ordinary steel. Each short length of pre-cut tubing, in sequence, is then bent into a preferred shape according to a predetermined pattern, which may be stored in computer memory, and when finished, an excess part of the tube is cut off to form a finished part. The excess, which has been trimmed off, is either discarded or recycled as scrap stock. This known process is less than ideal for several reasons. The labor cost of paying a skilled operator, to keep feeding in these short lengths of tubing stock, is relatively high. The safety risk of harm to that operator is higher than it would be if the procedure were automated, or if multiple pieces could be cut off of a single longer piece of tubing stock. Furthermore, in the above-described process, the amount of wasted steel scrap is excessively high.
While many types of tubing benders are known, and some machines exist which can both cut and bend tubing, such as are disclosed in U.S. Pat. No. 3,724,256 and 3,728,885, a need still exists in the art for an automated, synchronized machine, and method of use thereof, which is designed for both tube bending and cutting in a single operation, and which minimizes wasted excess. Ideally, this type of machine would be able to cut several usable finished parts off of a single extended length workpiece of tubing stock. Preferably, such a machine could be designed to have the capability to cut through a workpiece near a bend formed in the workpiece.